Hearing aid with anti feedback system
AssigneeOticon A/S
InventorsJohan Hellgren, Thomas Bo Nielsen
Life of this patent
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Abstract
A hearing aid with anti feed back system, the hearing aid including a signal path from at least one input transducer to an output transducer, a signal processing unit, acoustic environment detection capability, and a parameter generator that generates input to the setting of signal processing parameters to be used in the signal processing unit based on either manual input or from the results of acoustic environment detection, and an alert signal generator that generates an alert signal to the anti feed back system whenever one or more preselected input to the generation of signal processing parameters undergoes changes.
Claims18
Hearing aid with an anti feedback system that operates in one of at least two adaptation modes, a fast adaptation mode and a slow adaptation mode, the hearing aid comprising:
- a directional processing block that:
- receives input signals from two or more microphones,
- generates a DIR-signal with directional sensitivity and an OMNI-directional signal, and
- provides, as an output signal, an addition of the DIR and OMNI signals, where the addition is performed by a fader that subjects both signals to gain factors before addition, and wherein the gain, αomni applied to the OMINI-signal has a value between 0 and 1, inclusive, and wherein the gain applied to the DIR-signal is (1-α−omni),
- an acoustic environment detector that determines whether input signals from said microphones are directional or omni-directional,
- a trigger that generates an alert signal to the anti feed back system, said alert indicating the adaptation mode for the anti feedback system based on the value of αomni, and
- a controller that controls the trigger and the fader by generating a value for αomni based on input from the acoustic environment detector.
A method for preventing feedback in a hearing aid with an anti feedback system that operates in one of at least two adaptation modes, a fast adaptation mode and a slow adaptation mode, the method aid comprising:
- receiving input signals from two or more microphones;
- generating a DIR-signal with directional sensitivity and an OMNI-directional signal;
- providing, as an output signal, an addition of the DIR and OMNI signals, where the addition includes subjecting both signals to gain factors before adding them, and wherein the gain, αomni, applied to the OMNI-signal has a value between 0 and 1, inclusive, and wherein the gain applied to the DIR-signal is (1-αomni);
- determining whether input signals from said microphones are directional or omni-directional;
- generating an alert signal to the anti feed back system, said alert indicating the adaptation mode for the anti feedback system based on the value of αomni, and
- controlling the addition of the DIR and OMNI signals and generating an alert signal by generating a value for αomni based on results of said determining, such that the adaptation mode and the output signal are both governed by directional characteristics of the input signals from said microphones.
Dependencies are inferred from the claim text.